Clutch



B. LCEFFLER 2,251,143

CLUTCH- Filed Dec. 8, 1958 2 Sheets-Shea?l 1 July 29, 1941.

INV ENT OR. l runo'lpaaflef; n BY *www ATTORNEYS July 29, 1941. B, LOEFFLER CLUTCH g Filed'nec. 8,5 195s 2 Sheets-Sheet 2A' ATTORNEYS Patented July 29, 1941 S P' NT OFFICE CLUTCH Application @December 8, 1938, Serial No. 244,529

14 Claims.

This invention relates to clutches for power operated machinery and relates particularly to improvements in clutches of the type having a plurality of levers and cooperating fulcrums that disengage cooperating friction clutch elements in response to inward movement of an actuating collar.

An object of the invention is to provide a simple and efficient lever and fulcrum construction for disengaging the friction elements of a clutch.

Another object of the invention is to provide lever and fulcrum constructions for clutches that can be accurately adjusted to insure equal distribution of stresses and uniform release of the cooperating friction elements of the clutches.

Another object of the invention is to provide clutches having levers and fulcrums wherein the levers are not subjected to heavy stresses to maintain the friction 'clutch elements in engagement, and any tendency of the clutch elements to release because of increased centrifugal force is avoided.

An additional object of the invention is to provide clutches havingr cooperating friction elements that are normally retained in engagement by means of elements independent of the clutch actuating levers.

A further object of the invention is to provide clutches having individually adjustable lever and fulcrum elements that allow accurate control of the movement of the levers, uniform distribution of operating stresses and compensation for wear on the various elements of the clutches.

Other objects of the invention will be apparent from a description of a typical form of the invention.

Clutches embodying the present invention comprise cooperating friction clutch elements, an axially shiftable pressure plate, resilient means for urging the pressure plate and friction elements into clutching engagement, a plurality of levers for withdrawing the pressure plate to release the clutch elements from clutching engagement, and adjustable connections between the pressure plate and the lever-s for allowing independent adjustment of the levers whereby they may act equally to withdraw the pressure plate.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which:

Figure 1 is a View in'secton of a typical form of device embodying the invention taken on line I--I of Figure 3;

Figure 2 is a side view of the clutch partly broken away to show details thereof;

Figure 3 is a View of the opposite lside of the clutch with one of the levers broken away to show details of the fulcrum construction; and

Figure 4 is a sectional View taken on line 4-4 of Figure 3.

The form of clutch illustrated in the drawings consists of a housing member I0 having a substantially disc-like end Il and a peripheral and annular flange I2. The housing I0 may be fixed in any suitable way such as by means of bolts I3 to a drive shaft I4, said bolts passing through an end plate I5 on the drive shaft and through the end Il of the housing. The housing I0 is provided with an inner annular flange I6 in which is mounted an anti-friction bearing Il for the reduced end I8 of a driven shaft I9.

Fixed to the inner surface of the disc-like portion II of the housing I0 is a detachable friction clutch element 20 of annular formation and having a plane clutch face 2|. The clutch element 20 is provided with outwardly projecting lugs 22 which are received closely in apertures 23 in the clutch housing i0 whereby relative rotation therebetween is prevented. The apertures 23 are longer than the lugs 22 and permit relative thermal expansion and adjustment of the clutch element 20 relatively to the housing I0. The clutch member 20 may be connected to the housing I0 by means of a plurality of set screws 2d which allow the clutch element 2t to be removed and resurfaced or replaced when worn. The apertures in the housing I through which the set screws 24 pass are of somewhat greater diameter than the set screws and also permit thermal expansion and shifting of the clutch element 20 relatively to the housing I IJ to balance. the assembly.

Cooperating with the clutch element 2B is a clutch element `2&3 consisting of an annular ring 25 having clutch facing material 21 on opposite sides thereof. The ring 26 is fixed to a laterally projecting flange 28' on a hub 29 which is nonrotatably but slidably mounted on the shaft I9 by means of splines 30.

An annular pressure plate 3| is disposed on the side of the clutch element 25 opposite from the clutch element 20 andwhen urged into engagement with the clutch element 25 connects the drive shaft Ill to the driven shaft I9. The pressures plate 3l is normally urged into clutching engagement with the clutch element25 by means of a plurality of springs 32. The springs 32 are mounted in flanged cups 33 which are connected by welding, or in any other suitable Way, to the cover plate or closure 34. 'Ihe cover plate 34 is attached to the end of the flange l2 by means of a plurality oi set screws which permit ready removal of the cover plate when access to the interior of the housing is desired. The use of a plurality of springs engaging the pressure plate 3l results in uniform distribution of pressure throughout the entire area of the cooperating clutch elements 2G and 25 and pressure plate 3l, and thereby assures intimate and uniform engagement between these elements.

The pressure plate 3i is withdrawn to release the clutch by means of a plurality of clutch ac tuating levers 3S. Inasmuch as the levers and cooperating elements are identical in construction, only one lever assembly will be described. Each of the levers 36 consists of a long lever arm 37 having a reversely curved and outwardly directed end 38 formed of hardenedmaterial. The lever may be forged or cast as may be desired. The lever arm 3l is provided with an axially extending, reinforcing rib 39 which rigidies and strengthens the lever without unnecessarily increasing its weight, said rib terminating in oval or diverging flanges 40 which encircle an aperture 4l through which passes a post 42 xed to the cover plate 34. Adjacent the left-hand end of the lever, as viewed in Figure l, is a cup-shaped element 43 having its axis inclined to the horizontal. The cup-shaped member 43 has an inner lining of bearing material 44 provided with a hemispherical inner surface 45 in which is received a complementary hemispherical or ball-like fulcrum member 46. The lever 36 is rockable on the ball fulcrum 46 substantially universally. The fulcrum member 46 projects inwardly at an angle to a plate 41 that is fixed to the cover plate 34. Because of the inclination of the fulcrum member 46 and the element 43, centrifugal force generated during rotation of the clutch tends to urge them into tighter engagement and prevents the lever from becoming detached from the housing. The plate 4l is fixed to the cover partially by means of the post 42 and one or more rivets or pins 48 which prevent relative movement between the cover plate 34 and the plate 4l'. The outer end or short arm of the lever 36 is provided with spacedapart sidepieces 49 and a connecting endpieoe 49 deiining an aperture 5U through which passes the outer end of a link, such as eye-bolt 5l. inner end of the eye-bolt 5l is pivotally mounted on a pin 52 which extends between spaced lugs 53 and 54 that project from the outer surface of the pressure plate 3l. The lugs 53 and 54 are so spaced that they closely engage the edges of an aperture 55 in the cover plate, thus coupling the pressure plate 3| to the housing l0 and cover plate 34 for rotation therewith but allowing relative axial movement therebetween. As best shown in Figures 1 and 4, the upper end of the eye-bolt 5l is provided with threads 55 and a longitudinally extending key-way 5l. Mounted on the outer end of the eye-bolt 5| is a substantially wedge-shaped fulcrum element 58 having a rounded and angularly disposed lower fulcrum edge 59 which engages in notches or recesses 8B in the sidepieces 49 of the lever 36. The fulcrum member 58 is provided with a key Si which is received in the key-way 5l and thus cannot rotate relatively to the eye-bolt 5|. The fulcrum element 58 may be adjusted axially of the eyebolt 5I by means of a nut 62 which is retained in adjusted position by means of a lock washer 63. By adjusting the fulcrum elements 58 axially of the eye-bolt the inner ends 38 of the levers 36 The 'H may be brought into any desired adjusted posi tion for engagement with a ring E5 on a clutch actuating collar 64 which is shiftable axially of the shaft I9. The ring 65 which is L-shaped in cross-section is supported on the collar 64 by means of anti-friction bearings 6G whereby upon engagement of the ring 55 with the ends of the lever 38 it may rotate relatively to the shaft I9 and the collar 64.

In order to prevent unnecessary movement of the levers 36 and also to maintain them in their adjusted position, they may be engaged by a spring 6'.' which is mounted on the post 42 and normally urges the levers in clockwise direction, as viewed in Figure 1, about the fulcrum ball 46, thus exerting a light stress on the pressure plate and maintaining the lever 36 in engagement with fulcrum element 5B. The spring 6l thus prevents swinging and rotating of the levers 36. The spring 6l is retained in compression on the post 42 by means of a cap washer $8 and a cross pin 69 extending through the post and over the washer.

The construction described above may be readily adjusted by means of the fulcrum elements 58 so that when the levers 36 are rocked by means of the clutch actuating collar 64 the pressure plate is withdrawn without rocking or without a greater stress being exerted on one lever than on the others. Likewise, as the clutch elements 25 and 2B and the pressure plate wear, these fulcrum elements may be adjusted to realign the inner ends of the levers. Wear on the fulcrum member and the levers may be compensated for by adjustment of the fulcrum element 58 which is at all times readily accessible.

Inasmuch as clutches tend to become heated during operation, provision is made for cooling clutches embodying the invention. The cover plate 34 is provided with a central opening lll dened by an inwardly projecting iiange 7| and the wall I2 of the housing li) has a plurality of non-radially extending apertures l2 therein. The end Il of the housing also is provided with a series of apertures 73. During operation of the clutch, air may pass through the openings over the pressure plate and around the clutch elements, thus reducing their temperature and prolonging the life of the faces of the clutch elements.

The various elements forming the clutch are simple, sturdy, and can be readily assembled. Such parts as may need replacement may be readily removed and others substituted without special machining operations.

It will be understood that there may be variations made in the form of the various elements of the clutch and that the size and shape of the various parts may be varied without departing from the invention. Therefore, the embodiment ofthe clutch described above should be considered as illustrative only and not as limiting the scope of the following claims.

I claim:

l. A clutch comprising a housing, relatively shiltable clutch elements in said housing, means including a movable pressure member' normally urging said clutch elements into engagement, a plurality ol' levers rockably supported on the exterior of said housing :for withdrawing the pressure member to allow the clutch members to clisengage, a plurality oi link members pivotally connected to said pressure plate, and fulcrum elements comprising wedge-shaped followers on the link members adjustable axially of said link members and engaging said levers.

2. A clutch comprising relatively shiftable clutch elements, means including a movable pressure member normally urging said clutch elements into engagement, a housing for said clutch elements andvsaid pressure member, a plurality of fulcrum members on the exterior of said housing and inclined inwardly at an angle to the said housing, levers for withdrawing said pressure member to allow disengagement of the clutch elements rockably supported on said fulcrum members whereby the centrifugal force generated during rotation of the clutch elements will urge the said levers into closer engagement with the said fulcrum members, links connecting the outer extremities of said levers to said pressure member, and resilient means engaging said levers inwardly of said fulcrum members and urging them in a direction to withdraw said pressure plate.

3. A clutch comprising relatively shiftable clutch elements, means including a movable pressure member normally urging said clutch elements into engagement, a housing for said clutch, a plurality of ball-like fulcrum members xed to the exterior of said housing, levers for Withdrawing said pressure member, semi-spherical sockets on said levers for receiving said fulcrum members and permitting substantially universal movement thereon, resilient means for maintaining the said f levers in engagement with the said fulcrum members, means connecting the outer ends of said levers to said pressure member, and means engageable with the inner ends of said levers for rocking them about the fulcrum members to withdraw the pressure plate.

4. The clutch set forth in claim 3, in which the means connecting the outer ends of the levers to the pressure member comprise, links connected to said pressure member, fulcrum elements shiftable axially of said links and engaging said levers, resilient means for maintaining said levers in engagement with the said fulcrum elements, means for adjusting said fulcrum elements axially of said links to equalize the stress exerted on the *l said levers upon rocking thereof to withdraw the pressure plate.

5. A clutch comprising relatively shiftable clutch elements, means including a shiftable pressure member normally urging said clutch elements into engagement, a housing for said clutch elements and pressure plate, a plurality of hemispherical fulcrum elements on said housing, levers having hemispherical sockets engaging rockably mounted on said fulcrum elements for withdrawing said pressure plate, projections on said pressure plate engaging the said housing and connecting the housing and pressure plate for mutual rotation, links connecting the outer ends of the levers to said projections and springs supported on said housing engaging and tending to rock the levers about the fulcrums in the direction required to withdraw the pressure plate.

6. A clutch for disengageably connecting a drive shaft and a coaxial driven shaft comprising a housing having an inner clutch surface fixed to said drive shaft, a clutch member non-rotatably connected to and shiftable axially of said driven shaft between positions engaged with and disengaged from said clutch surface, means including a pressure plate normally urging said clutch member into engagement with said clutch surface, hemispherical fulcrum elements on said housing, levers mounted on said fulcrum elements for substantially universal movement relavtively thereto and extending radially with respect to :and having free inner ends adjacent said driven shaft, links connecting the outer ends of said levers to said pressure plate, and means shiftable axially of said shafts into engagement with the inner ends of said levers to withdraw the pressure plate and allow said clutch member to disengage from said clutch surface.

7. In a clutch including a housing, relatively shiftable clutch elements and a pressure member normally urging said clutch elements into engagement, the combination of a plurality of hemispherical fulcrum members fixed to the said housing, the axes of the said members being inclined inwardly towards the axis of the said clutch, a plurality of levers having cup-shaped portions receiving the inclined fulcrum members and substantially universally movable thereon and link means connecting the levers to the said pressure plate.

8. In a clutch including a housing, relatively shiftable clutch elements and a pressure member normally urging said clutch elements into engagement, the combination of a plurality of hemispherical fulcrum members xed to the exterior of said housing, a plurality of levers having cup-shaped portions receiving the fulcrum members and substantially universally movable thereon and links pivotally connecting the pressure plate and said levers.

9. In a clutch including a housing, relatively shiftable clutch elements and a pressure member normally urging said clutch elements into engagement, the combination comprising a plurality of ball-like fulcrum members, a plurality of levers rockably mounted on said fulcrum members, links connected to the pressure plate, wedge-shaped fulcrum elements on the said links engaging said levers and resilient means normally urging said levers against the said ball-like and wedge-shaped fulcrum elements.

10. In a clutch including a housing, relatively shiftable clutch elements and a pressure member normally urging said clutch elements into engagement, means for withdrawing the pressure plate from contact with the clutch elements comprising a plurality of substantially hemispherical fulcrum members fixed to the said housing, a plurality of levers rockably mounted on the said fulcrum members, links pivotally connected to the said pressure plate, wedge-shaped fulcrum elements adjustably mounted on said links and engaging said levers, springs normally urgingr said levers against said wedge-shaped fulcrum elements and means for rocking said levers to withdraw the pressure plate.

11. A clutch comprising a housing, relatively shiftable clutch elements in said housing, a pressure member normally urging said clutch elements into engagement, fulcrum members on the housing, levers supported on the said fulcrum members for withdrawing the pressure member to allow the clutch members to disengage, link members connected to the pressure member, fulcrum elements on the link members and engaging the extremities of the said levers, and resilient means xed on the housing for urging the levers against the fulcrum members and the lever extremities against the said fulcrum elements to minimize sliding movement therebetween.

12. A clutch comprising a housing, relatively shiftable clutch elements in said housing, a pressure member normally urging said clutch elements into engagement, fulcrum members on the housing, levers supported on the said fulcrum members for withdrawing the pressure member to allow the clutch members to disengage, link members pivotally connected to the pressure member, fulcrum elements on the link members and engaging the extremities of the said levers, and resilient means xed on the housing for urging the lever extremities against the said fulcrum elements.

13. In a clutch, the combination of a flywheel having a disc-like portion formed with apertures therein elongated radially of said portion, an annular metallic member having a clutch face detachably secured to the said flywheel, a plurality of lugs on the said member disposed in the said elongated apertures in the said disc-like portion and engaging the sides thereof to prevent relative rotation therebetween, said apertures permitting expansion and contraction of said member responsive to temperature variation.

14. In a clutch, the combination of a flywheel having a disc-like portion formed with apertures therein, an annular metallic member having a clutch face, means in said apertures for detachably securing the said member to the said disclike portion, the said means being of smaller dimensions radially of the said portion than the said apertures to permit of contraction and expansion of the said member relative to the said disc-like portion, in response to temperature variations, said means being in engagement with the sides of said apertures for preventing relative rotation of the members while permitting relative radial expansion therebetween.

BRUNO LOEFFLER. 

